ASTM A334 Grade 6 Steel Tubes of smaller than 1 ⁄ 2 in. [12.7 mm] in outside diameter, seamless and welded, carbon and alloy-steel tubes intended for use at low temperatures. The tubes shall be made by the seamless or automatic welding process with no addition of filler metal in the welding operation.
ASTM A334 Grade 6 Low-Temperature Seamless and Welded Tubes
Standad:ASTM A334/A334M
Standard Specification for
Seamless and Welded Carbon and Alloy-Steel Tubes for Low-Temperature Service
ASTM A334 Grade 6 Steel Tubes of smaller than 1 ⁄ 2 in. [12.7 mm] in outside diameter, seamless and welded, carbon and alloy-steel tubes intended for use at low temperatures.
Materials and Manufacture
The tubes shall be made by the seamless or automatic welding process with no addition of filler metal in the welding operation.
Heat Treatment
Normalize by heating to a uniform temperature of not less than 1550 °F [845 °C] and cool in air or in the cooling chamber of an atmosphere controlled furnace.
For the seamless process only, reheat and control hot working and the temperature of the hot-finishing operation to a finishing temperature range from 1550 to 1750 °F [845 to 955°C] and cool in a controlled atmosphere furnace from an initial temperature of not less than 1550 °F [845 °C].
Chemical Composition
| Element |
Composition, % |
| Grade 6 A |
| Carbon, max |
0.30 |
| Manganese |
0.29–1.06 |
| Phosphorus, max |
0.025 |
| Sulfur, max |
0.025 |
| Silicon |
0.10 min |
| Nickel |
… |
| Chromium |
… |
| Copper |
… |
| Cobalt |
… |
| Molybdenum |
… |
A For each reduction of 0.01 % carbon below 0.30 %, an increase of 0.05 % manganese above 1.06 % will be permitted to a maximum of 1.35 % manganese.
Mechanical Properties
| |
Grade 6 |
| ksi |
MPa |
| Tensile Strength, min |
60 |
415 |
| Yield Strength, min |
35 |
240 |
| Rockwell |
B 90 |
| Brinell |
190 |
Mechanical property requirements do not apply to tubing smaller than 1 ⁄ 8 in. [3.2 mm] in outside diameter and with a wall thickness under 0.015 in.[0.4 mm].
Impact Temperature
| Grade |
Impact Test Temperature |
| °F |
°C |
| 6 |
−50 |
−45 |
Mechanical Tests
Tension Test
Flattening Test
Flare Test (Seamless Tubes)
Flange Test (Welded Tubes)
Reverse Flattening Test
Hardness Test
Impact Tests
Hydrostatic or Nondestructive Electric Test
Manufacture: the tubes shall be made by the seamless process and shall be either hot-finished or cold-finished, as specified.
Heat Treatment: all seamless tubes shall be treated to control their microstructure in accordance with one of the following methods:
a: Normalize by heating to a uniform temperature of not less than 1550°F [845°C] and cool in air or in the cooling chamber of an atmosphere controlled furnace.
b: Reheat and control hot working and the temperature of the hot-finishing operation to a finishing temperature range from 1550 to 1750°F [845 to 955°C] and cool in a controlled atmosphere furnace from an initial temperature of not less than 1550 °F [845°C].
Inspection & Test: chemistry composition analysis, tension test, flattening test, flaring test, hardness test, impact test, NDT, surface inspection and dimension check. |
Length: 5800mm; 6000mm; 6096mm; 7315mm; 11800mm; and so on.
Max developed length: 30 meters, also U bending, finning, studded process can be provided.
| ASTM A334 Seamless Alloy Steel Pipes for Low Temperature Use,ASTM A334/A334M specification covers several grades of minimum wall-thickness, seamless and welded, carbon and alloy-steel tubes intended for use at low temperatures. Some product sizes may not be available under this specification because heavier wall thicknesses have an adverse affect on low-temperature impact properties. |
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